Optical Fingerprint Module

ABSTRACT

An optical fingerprint sensor module comprises: an optical fingerprint sensor, the optical fingerprint sensor having a non-opaque substrate and a device layer located on a surface of the non-opaque substrate, the device layer having a pixel area, the pixel area having a plurality of pixels, each pixel having a non-opaque area and a light blocking area, the light blocking area having a photosensitive element, the non-opaque area enabling lights to transmit through the pixel area of the device layer; a protection layer located above the optical fingerprint sensor; and a backlight source located under the pixel area, an included angle formed between a light emitted from the backlight source and an upper surface of the protection layer being an acute angle. The optical fingerprint module has an improved structure and enhanced performance.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of priority to Chinese PatentApplication No. 201610008090.8, filed on Jan. 7, 2016, and entitled“OPTICAL FINGERPRINT SENSOR MODULE”, the entire disclosure of which areincorporated herein by reference.

TECHNICAL FIELD

The present disclosure generally relates to optical fingerprintidentification field, and more particularly, to an optical fingerprintmodule.

BACKGROUND

Fingerprint imaging recognition technology is used to realizeidentification by capturing fingerprint images of a person using opticalfingerprint sensors and then determining whether the fingerprint imagesmatch those stored in a system before. Due to its convenience in use anduniqueness of human fingerprints, the fingerprint recognition technologyhas been widely applied to various fields, such as safety inspectionfield (for example, public security bureau or customs), entrance guardsystems in buildings, consumption goods field (for example, personalcomputers or mobile phones), and the like. The fingerprint recognitiontechnology includes optical imaging, capacitive imaging, ultrasonicimaging and the like, among which, the optical fingerprint recognitiontechnology is advantageous in imaging quality and device cost.

As shown in FIG. 1, an existing optical fingerprint module includes abacklight source 110, an optical fingerprint sensor 120, a protectivelayer 130 and a shell (not shown is FIG. 1). To acquire a fingerprintimage, a finger 140 of a person is placed on the protective layer 130.Output light 111 of the backlight source 110 (upward arrows in FIG. 1represent the output light 111, and the upward arrows are surrounded bydotted lines to be marked in a unified manner) penetrates through theoptical fingerprint sensor 120 and the protective layer 130, and isreflected and transmitted at a contact interface between the finger 140and the protective layer 130. Reflected light 112 (downward arrows inFIG. 1 represent the reflected light 112, and the downward arrows aresurrounded by dotted lines to be marked in a unified manner) penetratesthrough the protective layer 130 and irradiates onto the opticalfingerprint sensor 120. Circuits (not shown in FIG. 1) inside theoptical fingerprint sensor 120 perform photoelectric conversion andsignal processing to realize acquisition of the fingerprint image. As acontact part between the finger 140 and the protective layer 130reflects fingerprint characteristics of the person, and characteristicof the contact part can directly indicate characteristic of thereflected light 112, the image acquired by the optical fingerprintsensor 120 directly reflects the fingerprint characteristics of theperson.

More content related to optical fingerprint sensors can be found inChinese Utility Model Patent with a publication No. CN203405831U.

Structures and performance of existing optical fingerprint modules needto be improved.

SUMMARY

In embodiments of the present disclosure, an optical fingerprint moduleis provided with an optimized structure to improve performance.

In an embodiment of the present disclosure, an optical fingerprintmodule is provided, including: an optical fingerprint sensor including anon-opaque substrate and a device layer located on a surface of thenon-opaque substrate, wherein the device layer includes a pixel areaconsisting of a plurality of pixels, each of the plurality of pixelsincludes a non-opaque region and a light blocking region, the lightblocking region includes a photosensitive element, and the non-opaqueregion enables light to penetrate through the pixel area of the devicelayer; a protective layer disposed above the optical fingerprint sensor;and a backlight source disposed below the pixel area, wherein an acuteangle is formed between light emitted from the backlight source and anupper surface of the protective layer.

Optionally, a first optical adhesive layer may be disposed between theoptical fingerprint sensor and the protective layer, wherein the lightemitted from the backlight source penetrates through the non-opaquesubstrate, then penetrates through the device layer via the non-opaqueregion, enters the first optical adhesive layer, and finally enters theprotective layer from the first optical adhesive layer.

Optionally, a first optical adhesive layer may be disposed between theoptical fingerprint sensor and the protective layer, wherein the lightemitted from the backlight source penetrates through the device layervia the non-opaque region, then penetrates through the non-opaquesubstrate, enters the first optical adhesive layer, and finally entersthe protective layer from the first optical adhesive layer.

Optionally, the backlight source may include at least one Light EmittingDiode (LED), and light of the LED is near-ultraviolet light, purplelight, blue light, green light, yellow light, red light, near-infraredlight or white light.

Optionally, the backlight source may include at least two LEDs which aresymmetrically arranged below the optical fingerprint sensor, and lightof the LEDs may be near-ultraviolet light, purple light, blue light,green light, yellow light, red light, near-infrared light or whitelight.

Optionally, a light focusing lens may be disposed in front of a lightemitting surface of the LED, the light focusing lens may be capable offocusing light of the LED into parallel light or near-parallel light,and the light emitted from the backlight source enters the lightfocusing lens and then enters the optical fingerprint sensor.

Optionally, a light anti-reflection layer, which is capable ofincreasing a proportion of the light emitted from the backlight sourcewhich enters into the optical fingerprint sensor, may be disposed on asurface of the optical fingerprint sensor which is close to thebacklight source.

Optionally, a non-opaque dielectric layer may be disposed between theoptical fingerprint sensor and the backlight source, and the lightemitted from the backlight source enters the non-opaque dielectric layerand then enters the optical fingerprint sensor.

Optionally, a side surface or a lower surface of the non-opaquedielectric layer may be a light focusing surface, and the light emittedfrom the backlight source enters the non-opaque dielectric layer fromthe light focusing surface which focuses the light emitted from thebacklight source into parallel light or near-parallel light.

Optionally, a second optical adhesive layer may be disposed between theoptical fingerprint sensor and the non-opaque dielectric layer, whereinthe light emitted from the backlight source enters the second opticaladhesive layer from the non-opaque dielectric layer, and then enters theoptical fingerprint sensor from the second optical adhesive layer.

Optionally, a light anti-reflection layer, which is capable ofincreasing a proportion of the light emitted from the backlight sourcewhich enters into the non-opaque dielectric layer, may be disposed onthe side surface or the lower surface of the non-opaque dielectriclayer.

Optionally, the non-opaque dielectric layer may include glass, plasticor optical adhesive.

Optionally, the non-opaque dielectric layer may have a refraction indexabove 1.2.

Optionally, the light focusing surface of the non-opaque dielectriclayer may be an oblique surface, a spherical crown surface, anellipsoidal crown surface, a conical side surface or a pyramid sidesurface.

Optionally, the protective layer may include a single layer or multiplelayers, wherein a light filtering layer is disposed on at least one ofthe upper surface of the protective layer, a lower surface of theprotective layer and an upper surface of the optical fingerprint sensor.

Optionally, the device layer may further include a plurality of scanninglines arranged in a first axial direction and a plurality of data linesarranged in a second axial direction, wherein the plurality of scanninglines and the plurality of data lines define a plurality of grids, andthe pixels are located in the grids.

Optionally, the first optical adhesive layer may be a heat curingoptical adhesive layer, a photo curing optical adhesive layer or anoptical double-sided adhesive tape.

Optionally, the second optical adhesive layer may be a heat curingoptical adhesive layer, a photo curing optical adhesive layer or anoptical double-sided adhesive tape.

Embodiments of the present disclosure may provide following advantages.

In embodiments of the present disclosure, an optical fingerprint moduleis provided, including: an optical fingerprint sensor including anon-opaque substrate and a device layer located on a surface of thenon-opaque substrate, wherein the device layer includes a pixel areaconsisting of a plurality of pixels, each of the plurality of pixelsincludes a non-opaque region and a light blocking region, the lightblocking region includes a photosensitive element, and the non-opaqueregion enables light to penetrate through the pixel area of the devicelayer; a protective layer disposed above the optical fingerprint sensor;and a backlight source disposed below the pixel area, wherein an acuteangle is formed between light emitted from the backlight source and anupper surface of the protective layer. By disposing the backlight sourcebelow the pixel area, the light emitted from the backlight source firstpenetrates through the optical fingerprint sensor (penetrating throughthe optical fingerprint sensor includes penetrating through thenon-opaque substrate, or penetrating through both the non-opaquesubstrate and the pixel area) and then reaches the protective layer,where the acute angle is formed between the light emitted from thebacklight source and the upper surface of the protective layer. Ashaving the acute angle with the upper surface of the protective layer,all the light reaching the upper surface of the protective layer may bereflected at a contact interface between the upper surface of theprotective layer and a fingerprint at corresponding shift distances, andmost effective reflected light irradiates into pixels in the pixel areawhich have nearly same shift distances from corresponding reflectionpoints. Therefore, by the above optical fingerprint module without alight guiding plate, fingerprint image recognition may be well achievedby acquiring a clear fingerprint image, a structure of the opticalfingerprint module may be simplified, and cost may be reduced.

Further, the backlight source may include two LEDs. During thefingerprint image acquisition, any one of the two LEDs may be selectedas an imaging light source of the fingerprint image, or light emittedfrom the two LEDs may be used in turn for imaging, and afterward,corresponding image calculation is performed, so that a fingerprintimage may be acquired with less distortion and higher accuracy, and thusperformance of the optical fingerprint module may be further improved.

Further, the surface of the optical fingerprint sensor which is close tothe backlight source may further have a light anti-reflection layerthereon, and the light anti-reflection layer is capable of increasingthe proportion of light emitted from the backlight source which entersinto the optical fingerprint sensor. In this way, the fingerprint imagemay be acquired using more light to have higher quality and accuracy,and thus performance of the optical fingerprint module may be furtherimproved.

Further, a light focusing lens which is capable of focusing the lightemitted from the backlight source into parallel light or near-parallellight may be disposed in front of the light emitting surface of thebacklight source. The light emitted from the backlight source enters thelight focusing lens, and then enters the optical fingerprint sensor. Asa result, the fingerprint image may be acquired using the parallel lightor the near-parallel light to have less distortion and higher accuracy,and thus performance of the optical fingerprint module may be furtherimproved.

Further, a non-opaque dielectric layer may be further disposed betweenthe optical fingerprint sensor and the backlight source. The non-opaquedielectric layer has a refractive index greater than that of air, andlight is enabled to enter the non-opaque dielectric layer from a sidesurface of the non-opaque dielectric layer, so that the light emittedfrom the backlight source reaches the upper surface of the protectivelayer with a greater incident angle (that is, the light can reach theupper surface of the protective layer in a direction closer to beparallel to the upper surface of the protective layer). When theincident angle of the light is larger than a certain angle, totalreflection occurs (i.e., when the incident angle is greater than acritical angle, the light is totally reflected at a contact interfacebetween the protective layer and air) to greatly improve quality of theimage, so that the fingerprint image may be acquired with higher qualityand accuracy, and thus performance of the optical fingerprint module maybe further improved.

Furthermore, the side surface or the lower surface of the non-opaquedielectric layer may serve as a light focusing surface which is capableof focusing light of the backlight source into parallel light ornear-parallel light. The light emitted from the backlight source entersthe non-opaque dielectric layer from the light focusing surface, andthen enters the optical fingerprint sensor. As a result, the fingerprintimage may be acquired using the parallel light or the near-parallellight to have less distortion and higher accuracy, and thus performanceof the optical fingerprint module may be further improved.

Further, the side surface or the lower surface of the non-opaquedielectric layer may further have a light anti-reflection layer formedthereon, and the light anti-reflection layer is capable of increasingthe proportion of the light emitted from the backlight source whichenters the non-opaque dielectric layer. Therefore, the fingerprint imagemay be acquired using more light to have higher quality and accuracy,and thus performance of the optical fingerprint module may be furtherimproved.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 schematically illustrates a structural diagram of an opticalfingerprint module in existing techniques;

FIG. 2 schematically illustrates a top view of an optical fingerprintsensor in existing techniques;

FIG. 3 schematically illustrates a sectional view of the opticalfingerprint sensor along an A-A line as shown in FIG. 2;

FIG. 4 schematically illustrates an enlarged diagram of a structuresurrounded by a dotted box 220A in the optical fingerprint sensor asshown in FIG. 2;

FIG. 5 schematically illustrates a sectional view of an opticalfingerprint module where the optical fingerprint sensor in FIG. 4 islocated along a B-B dotted line in FIG. 2;

FIG. 6 schematically illustrates a top view of an optical fingerprintsensor and a backlight source in an optical fingerprint module accordingto an embodiment;

FIG. 7 schematically illustrates a sectional view of the opticalfingerprint module according to the embodiment shown in FIG. 6;

FIG. 8 schematically illustrates a sectional view of an opticalfingerprint module according to an embodiment;

FIG. 9 schematically illustrates a sectional view of an opticalfingerprint module according to an embodiment;

FIG. 10 schematically illustrates a sectional view of an opticalfingerprint module according to an embodiment;

FIG. 11 schematically illustrates a sectional view of an opticalfingerprint module according to an embodiment;

FIG. 12 schematically illustrates a sectional view of an opticalfingerprint module according to an embodiment; and

FIG. 13 schematically illustrates a sectional view of an opticalfingerprint module according to an embodiment.

DETAILED DESCRIPTION

An existing optical fingerprint sensor has structures as shown in FIGS.2 and 3. FIG. 2 schematically illustrates a top view of the opticalfingerprint sensor, and FIG. 3 schematically illustrates a sectionalview of the optical fingerprint sensor along an A-A line as shown inFIG. 2. The optical fingerprint sensor includes a glass substrate 220,and a pixel array region 231 and a peripheral circuit which are disposedon the glass substrate 220. The peripheral circuit includes a drivingcircuit 234, a signal readout chip 232 and a flexible printed circuitboard 233. The pixel array region 231 includes a pixel array forreceiving, focusing and temporarily storing optical signals. Theperipheral circuit further includes a flexible printed circuit boardbonding area 233A, and connecting wires (not shown in FIG. 3) among thepixel array region 231, a bonding region of the signal readout chip 232and the flexible printed circuit board bonding area 233A.

FIG. 4 schematically illustrates an enlarged diagram of a structuresurrounded by a dotted box 220A in the optical fingerprint sensor asshown in FIG. 2. Referring to FIG. 4, the pixel array region 231includes a plurality of pixels (not labeled in FIG. 4) arranged in arow-column array, and the row and column of the pixel are defined by aplurality of scanning lines 2311 in a first axial direction and aplurality of data lines 2312 in a second axial direction. Each pixelincludes a signal control switch 2313, a photoelectric conversion device2314 and a non-opaque region (not labeled in FIG. 4). Correspondingbacklight can penetrate through the optical fingerprint sensor via thenon-opaque region. The scanning lines 2311 are connected to the drivingcircuit 234, and the data lines 2312 are connected to the bonding regionof the signal readout chip 232.

FIG. 5 schematically illustrates a sectional view of an opticalfingerprint module where the optical fingerprint sensor in FIG. 4 islocated along a B-B dotted line in FIG. 2. The B-B dotted line passesthrough pixels P1 and P2 in FIG. 4. Referring to FIG. 5, the opticalfingerprint module includes a backlight source 200, a light guidingplate 210, an optical fingerprint sensor (not labeled), an adhesivelayer 240 and a protective layer 250. The optical fingerprint sensorincludes a non-opaque substrate 220 and a device layer 230 disposed on asurface of the non-opaque substrate 220. Each of the pixels P1 and P2includes a light blocking region 2301 and a non-opaque region 2302.

In the existing optical fingerprint module, the backlight source 200 isgenerally an LED which is arranged at one side surface of the lightguiding plate 210, and light emitted from the backlight source 200irradiates into the light guiding plate 210 in a certain open angle.Small hemispherical or semi-ellipsoidal bumps 211 are arranged on abottom surface of the light guiding plate 210. When irradiating onto thesmall bumps 211, light inside the light guiding plate 210 may bescattered, so that a direction of the light is changed to realize upwardirradiation. Further, a reflecting coating (not shown in FIG. 5) may bedisposed on bottom (below the small bumps 211) and side surfaces of thelight guiding plate 210. When the light reaches the bottom or sidesurfaces of the light guiding plate 210, most of the light may bereflected back to the light guiding plate 210, and scattered upward bythe small bumps 211.

However, as the light scattered upward by the small bumps 211 at thebottom surface of the light guiding plate 210 has a certain angledistribution range, some of the light may be vertically upward, whilesome is titled upward, even close to a horizontal direction (as thelight 200 a in FIG. 5). When the light 200 b irradiates onto theprotective layer 250 in a nearly vertical direction (that is, the lightis perpendicular to an upper surface of the protective layer 250), andreflected and transmitted at a contact interface between a finger 260and the protective layer 250, the reflected light may irradiate back tothe optical fingerprint sensor in a nearly vertical direction, andfurther irradiate to pixels or nearby pixels under the fingerprint, togenerate a relatively clear fingerprint image. While the light 200 a isdeviated from a vertical direction, even close to a horizontaldirection, the reflected light may irradiate to pixels far away frompixels right under the fingerprint. Therefore, signals of the light 200a and the light 200 b may be mixed together, so that a blurredfingerprint image may be formed.

Besides, the protective layer 250 may be relatively thick to achievecertain reliability. Therefore, for the existing optical fingerprintmodules, it is almost unavoidable that relatively blurred fingerprintimages are formed and even no fingerprint image can be formed.

Therefore, embodiments of the present disclosure provide an opticalfingerprint module. By disposing the backlight source below the pixelarea, the light emitted from the backlight source first penetratesthrough the optical fingerprint sensor (penetrating through the opticalfingerprint sensor includes penetrating through the non-opaquesubstrate, or penetrating through both the non-opaque substrate and thepixel area) and then reaches the protective layer, where the acute angleis formed between the light emitted from the backlight source and theupper surface of the protective layer. As having the acute angle withthe upper surface of the protective layer, all the light reaching theupper surface of the protective layer may be reflected at a contactinterface between the upper surface of the protective layer and afingerprint according to corresponding shift distances, and mosteffective reflected light irradiates into pixels in the pixel area whichhave nearly same shift distances from corresponding reflection points.Therefore, by the above optical fingerprint module without a lightguiding plate, fingerprint image recognition may be well achieved byacquiring a clear fingerprint image, a structure of the opticalfingerprint module may be simplified, and cost may be reduced.

In order to clarify the object, characteristic and advantages ofembodiments of the present disclosure, embodiments of present disclosurewill be described clearly in detail in conjunction with accompanyingdrawings.

In an embodiment, an optical fingerprint module is provided. FIG. 6schematically illustrates a top view of an optical fingerprint sensor320 and a backlight source 330 in the optical fingerprint module (i.e.,a top view of the optical fingerprint module excluding a protectivelayer 310). FIG. 7 schematically illustrates a sectional view of theoptical fingerprint module. It should be noted that, FIG. 7schematically illustrates a sectional view of the optical fingerprintmodule along a C-C line in FIG. 6.

Referring to FIGS. 6 and 7, the optical fingerprint module includes theprotective layer 310, the optical fingerprint sensor 320 and thebacklight source 330.

It should be noted that FIG. 7 shows the optical fingerprint sensor 320as an integral structure. In fact, the optical fingerprint sensor 320includes a plurality of portions. As shown in the top view of theoptical fingerprint sensor 320 in FIG. 6, the optical fingerprint sensor320 includes a non-opaque substrate 322 and a pixel area 321. Stillreferring to FIG. 6, in some embodiments, the optical fingerprint sensor320 includes a non-opaque substrate 322 and a device layer (not allshown, and not labeled) disposed on a surface of the non-opaquesubstrate 322, where the device layer includes the pixel area 321.

In some embodiments, the pixel area 321 is rectangular, where one sidelength of the pixel area 321 is E1, and the other adjacent side lengthis E2. The side length E1 and the side length E2 may be selectedaccording to practical requirements of products. The pixel area 321consists of a plurality of pixels (not shown in FIG. 6, and contentrelated to the pixels can be referred to the above descriptions of FIGS.4 and 5), and each pixel includes a non-opaque region and a lightblocking region. The light blocking region includes a photosensitiveelement, and the non-opaque region enables light to penetrate throughthe pixel area 321 of the device layer.

It should be noted that, other areas located at the periphery of thepixel area 321 in the device layer may also be arranged to benon-opaque. That is, the pixel area 321 is non-opaque due to thenon-opaque region of each pixel, while for an area except the pixel area321, the whole area or a portion of the area may be made as a non-opaquestructure, on the basis that a structure and a function of the area areguaranteed.

Referring to FIG. 7, the pixel area 321 is marked between two longdotted lines, representing that in a plane where the cross section inFIG. 7 is located, the pixel area 321 is located between the two longdotted lines of the optical fingerprint sensor 320, specifically, in alayer structure of the optical fingerprint sensor 320 between the twodotted lines (as shown in FIG. 6, the pixel area 321 is disposed on thenon-opaque substrate 322). An area between the two dotted lines underthe optical fingerprint sensor 320 is an area under the pixel area 321.In sectional views for other embodiments of the present specification,labeling of a pixel area is also carried out by adopting the abovemethod, and is not described in detail below.

Referring to FIG. 7, the protective layer 310 is disposed on the opticalfingerprint sensor 320, and the backlight source 330 is disposed belowthe pixel area 321, so that an acute angle is formed between lightemitted from the backlight source 330 and the upper surface of theprotective layer 310.

The light emitted from the backlight source 330 is shown asunidirectional arrows in FIG. 7. As the backlight source 330 is disposedbelow the pixel area 321, the backlight source 330 is located at oneside of the pixel area 321 in the top view in FIG. 6. Referring to FIG.7, an area under the pixel area 321 is an area between the two longdotted lines, while the backlight source 330 is disposed outside thearea. Therefore, in the sectional view in FIG. 7, in a horizontaldirection, there is a first distance D1 (which is also shown in FIG. 6)between the backlight source 330 and the area under the pixel area 321;and in a vertical direction, there is a second distance D2 between thebacklight source 330 and the optical fingerprint sensor 320. As thepixel area 321 is a portion of the optical fingerprint sensor 320, adistance between the backlight source 330 and the pixel area 321 in thevertical direction is certainly no less than the second distance D2.

From above, due to the first distance D1 and the second distance D2, thebacklight source 330 is certainly disposed below the pixel area 321. Itcould be understood that, the backlight source 330 being disposed belowthe pixel area 321 means that the backlight source 330 is disposed lowerthan but not right under the pixel area 321. In some embodiments, thefirst distance D1 and the second distance D2 may be adjusted to make thebacklight source 330 in a suitable position, so as to improve quality ofa fingerprint image formed by the optical fingerprint module.

It should be noted that, in other embodiments, if a non-opaque openangle of the backlight source 330 is large enough, or not all the pixelarea is required to be normally imaged, the backlight source 330 may bearranged right under the pixel area 321. Namely, in the top view, thebacklight source 330 is located at the edge of or in the pixel area 321,where the second distance D2 is zero or negative. In other embodiments,the backlight source may be arranged right under the pixel area.

In some embodiments, the backlight source 330 may include one LED, andlight of the LED is near-ultraviolet light, purple light, blue light,green light, yellow light, red light, near-infrared light or whitelight.

In some embodiments, the backlight source 330 may include at least twoLEDs which are symmetrically arranged below the optical fingerprintsensor 320, and light of the LEDs may be near-ultraviolet light, purplelight, blue light, green light, yellow light, red light, near-infraredlight or white light. When the backlight source 330 includes at leasttwo LEDs, the light of the LEDs may be the same, or totally different,or partially different.

As not shown in the figures, in some embodiments, a first opticaladhesive layer may be disposed between the optical fingerprint sensor320 and the protective layer 310, and the device layer is disposedbetween the non-opaque substrate 322 and the protective layer 310 (thefirst optical adhesive layer is disposed between the device layer andthe protective layer 310). The light emitted from the backlight source330 penetrates through the non-opaque substrate 322 first, and thenpenetrates through the device layer via the non-opaque region, thenenters the first optical adhesive layer, and then enters the protectivelayer 310 from the first optical adhesive layer.

In some embodiments, a first optical adhesive layer may be disposedbetween the optical fingerprint sensor 320 and the protective layer 310,and the non-opaque substrate 322 is disposed between the device layerand the protective layer 310 (the first optical adhesive layer isdisposed between the non-opaque substrate 322 and the protective layer310). The light emitted from the backlight source 330 penetrates throughthe device layer via the non-opaque region first, and then penetratesthrough the non-opaque substrate 322, then enters the first opticaladhesive layer, and then enters the protective layer 310 from the firstoptical adhesive layer.

In some embodiments, the first optical adhesive layer may be a heatcuring optical adhesive layer, a photo curing optical adhesive layer oran optical double-sided adhesive tape.

In some embodiments, the device layer may further include a plurality ofscanning lines arranged in a first axial direction and a plurality ofdata lines arranged in a second axial direction, wherein the pluralityof scanning lines and the plurality of data lines define a plurality ofgrids, and the pixels are located in the grids. Details may be referredto the above descriptions of FIGS. 4 and 5.

In some embodiments, the protective layer 310 may include a singlelayer. In some embodiments, the protective layer 310 may includemultiple layers. Besides, a light filtering layer may be disposed on atleast one of the upper surface of the protective layer 310, a lowersurface of the protective layer 310 and an upper surface of the opticalfingerprint sensor 320.

In the optical fingerprint module provided in embodiments of the presentdisclosure, by disposing the backlight source 330 below the pixel area321, the light emitted from the backlight source 330 first penetratesthrough the optical fingerprint sensor 320 (penetrating through theoptical fingerprint sensor 320 includes penetrating through thenon-opaque substrate 322, or penetrating through both the non-opaquesubstrate 322 and the pixel area 321) and then reaches the protectivelayer 310, where the acute angle is formed between the light emittedfrom the backlight source 330 and the upper surface of the protectivelayer 310. As having the acute angle with the upper surface of theprotective layer 310, all the light reaching the upper surface of theprotective layer 310 may be reflected at a contact interface between theupper surface of the protective layer 310 and a fingerprint according tocorresponding shift distances, and most reflected light irradiates intopixels in the pixel area 321 which have nearly same shift distances fromcorresponding reflection points. Therefore, by the above opticalfingerprint module without a light guiding plate, fingerprint imagerecognition may be well achieved by acquiring a clear fingerprint image,a structure of the optical fingerprint module may be simplified, andcost may be reduced.

In an embodiment, another optical fingerprint module is provided. FIG. 8schematically illustrates a sectional view of the optical fingerprintmodule. The optical fingerprint module includes a protective layer 410,an optical fingerprint sensor 420 and a backlight source. Details of theprotective layer 410 and the optical fingerprint sensor 420 may be foundin the descriptions of the protective layer 310 and the opticalfingerprint sensor 320 in the above embodiment. Other unreferencedstructures and content of the optical fingerprint module of theembodiment can also be referred to the above descriptions.

Same as the above embodiment as shown in FIGS. 6 and 7, in theembodiment as shown in FIG. 8, the backlight source is disposed belowbut not right under the pixel area 421, thus, an acute angle is formedbetween light emitted from the backlight source and an upper surface ofthe protective layer 410. Different from the above embodiment, in theembodiment as shown in FIG. 8, the backlight source includes two LEDs,an LED 430 and an LED 440. Light emitted from the LED 430 and the LED isshown with unidirectional arrows in FIG. 8. The LED 430 and the LED 440are located below the pixel area 421. In a top view of FIG. 8, the LED430 and the LED 440 are located out of the pixel area 421. In thesectional view shown in FIG. 8, an area where pixel area 421 is locatedis an area where the two long dotted lines are located, and the LED 430and the LED 440 fall outside the area.

Therefore, in the sectional view shown in FIG. 8, in a horizontaldirection, there is a first distance F1 between the LED 430 and the arearight under the pixel area 421; and in a vertical direction, there is asecond distance F2 between the LED 430 and the optical fingerprintsensor 420. As the pixel area 421 is a portion of the opticalfingerprint sensor 420, a distance between the LED 430 and the pixelarea 421 in the vertical direction is certainly no less than the seconddistance F2.

From above, due to the first distance F1 and the second distance F2, theLED 430 is certainly disposed below but not right under the pixel area421. In some embodiments, the first distance F1 and the second distanceF2 may be adjusted to make the LED 430 in a suitable position, so as toimprove quality of a fingerprint image formed by the optical fingerprintmodule.

Similarly, in the sectional view shown in FIG. 8, in the horizontaldirection, there is a first distance F3 between the LED 440 and the arearight under the pixel area 421; and in the vertical direction, there isa second distance F4 between the

LED 440 and the optical fingerprint sensor 420. As the pixel area 421 isa portion of the optical fingerprint sensor 420, a distance between theLED 440 and the pixel area 421 in the vertical direction is certainly noless than the second distance F4. From above, due to the first distanceF3 and the second distance F4, the LED 440 is certainly disposed belowbut not right under the pixel area 421. In some embodiments, the firstdistance F3 and the second distance F4 may be adjusted to make the LED440 in a suitable position, so as to improve quality of a fingerprintimage formed by the optical fingerprint module.

In some embodiments, if the backlight source includes two or more LEDs(such as including the LEDs 430 and 440), a distance between one of thetwo or more LEDs which is closest to the pixel area 421 and the pixelarea 421 may be taken as a distance between the backlight source and thepixel area 421.

In the embodiment, light emitted from the LEDs 430 and 440 may benear-ultraviolet light, purple light, blue light, green light, yellowlight, red light, near-infrared light or white light. The light emittedfrom the LEDs 430 and 440 may be the same or different. In someembodiments, the backlight source may include three or more LEDs whichmay be symmetrically arranged below the optical fingerprint sensor 420.For example, when the backlight source includes four LEDs, and a topview of the pixel area 421 is rectangular, the four LEDs may besymmetrically arranged at four sides below the pixel area 421. In someembodiments, light emitted from the LEDs may be near-ultraviolet light,purple light, blue light, green light, yellow light, red light,near-infrared light or white light. The light emitted from the LEDs maybe the same, or totally different, or partially different.

By the above embodiment, in the optical fingerprint module without alight guiding plate, fingerprint image recognition may be well achievedby acquiring a clear fingerprint image, a structure of the opticalfingerprint module may be simplified, and cost may be reduced. As thebacklight source includes the LEDs 430 and 440, light of any one LED maybe selected as the imaging light of fingerprint images in thefingerprint image acquisition, which leads to imaging effect similar tothat of the embodiment shown in FIGS. 6 and 7.

As light emitted from the two LEDs has a certain open angle range butare not parallel light, incident angles of the light reaching atdifferent areas on the upper surface of the protective layer may beslightly different. Accordingly, distances between pixels irradiated bythe reflected light at different areas on the upper surface of theprotective layer and corresponding reflection points may be slightlydifferent, which results in slight image distortion. The thicker theprotective layer is, the greater the distortion is. In some embodiments,light emitted from the two LEDs may be used in turn for imaging, andcorresponding image calculation is performed, so as to acquire afingerprint image with less distortion and higher accuracy, which mayfurther improve performance of the optical fingerprint module.

In some embodiments, when the backlight source includes more than twoLEDs, light emitted from the LEDs may be used in turn for imaging, andnoise reduction and compensation calculation are performed, so as toacquire a fingerprint image with higher quality and accuracy, which mayfurther improve performance of the optical fingerprint module.

In an embodiment, another optical fingerprint module is provided. FIG. 9schematically illustrates a sectional view of the optical fingerprintmodule. The optical fingerprint module includes a protective layer 510,an optical fingerprint sensor 520 and a backlight source 530.

Referring to FIG. 9, the backlight source 530 is disposed below a pixelarea 521, so that an acute angle is formed between light emitted fromthe backlight source 530 and an upper surface of the protective layer510.

The light emitted from the backlight source 530 is shown asunidirectional arrows in FIG. 9. As the backlight source 530 is disposedbelow the pixel area 521, the backlight source 530 is located at oneside of the pixel area 521 in the sectional view in FIG. 9. Stillreferring to FIG. 9, an area under the pixel area 521 is an area betweenthe two long dotted lines, while the backlight source 530 is disposedoutside the area. Therefore, in the sectional view in FIG. 9, in ahorizontal direction, there is a first distance G1 between the backlightsource 530 and the area under the pixel area 521; and in a verticaldirection, there is a second distance G2 between the backlight source530 and the optical fingerprint sensor 520. As the pixel area 521 is aportion of the optical fingerprint sensor 520, a distance between thebacklight source 530 and the pixel area 521 in the vertical direction iscertainly no less than the second distance G2.

From above, due to the first distance G1 and the second distance G2, thebacklight source 530 is certainly disposed below the pixel area 521. Itcould be understood that, the backlight source 530 being disposed belowthe pixel area 521 means that the backlight source 530 is disposed lowerthan but not right under the pixel area 521. In some embodiments, thefirst distance G1 and the second distance G2 may be adjusted to make thebacklight source 530 in a suitable position, so as to improve quality ofa fingerprint image formed by the optical fingerprint module.

More detailed structures of the optical fingerprint module can be foundin the above descriptions.

Different from the embodiment shown in FIG. 7, in the embodiment asshown in FIG. 9, a light anti-reflection layer 540, which is capable ofincreasing a proportion of the light emitted from the backlight source530 which enters into the optical fingerprint sensor 520, may bedisposed on a surface of the optical fingerprint sensor 520 which isclose to the backlight source 530.

By the above optical fingerprint module without a light guiding plate,fingerprint image recognition may be well achieved by acquiring a clearfingerprint image, a structure of the optical fingerprint module may besimplified, and cost may be reduced. Further, the surface of the opticalfingerprint sensor 520 which is close to the backlight source 530 mayfurther have the light anti-reflection layer 540 thereon, and the lightanti-reflection layer 540 is capable of increasing the proportion oflight emitted from the backlight source 530 which enters into theoptical fingerprint sensor 520. In this way, the fingerprint image maybe acquired using more light to have higher quality and accuracy, andthus performance of the optical fingerprint module may be furtherimproved.

In an embodiment, another optical fingerprint module is provided. FIG.10 schematically illustrates a sectional view of the optical fingerprintmodule. The optical fingerprint module includes a protective layer 610,an optical fingerprint sensor 620 and a backlight source 630.

Referring to FIG. 10, the backlight source 630 is disposed below a pixelarea 621, so that an acute angle is formed between light emitted fromthe backlight source 630 and an upper surface of the protective layer610.

The light emitted from the backlight source 630 is shown asunidirectional arrows in FIG. 10. As the backlight source 630 isdisposed below the pixel area 621, the backlight source 630 is locatedat one side of the pixel area 621 in the sectional view in FIG. 10.Still referring to FIG. 10, an area under the pixel area 621 is an areabetween the two long dotted lines, while the backlight source 630 isdisposed outside the area. Therefore, in the sectional view in FIG. 10,in a horizontal direction, there is a first distance H1 between thebacklight source 630 and the area under the pixel area 621; and in avertical direction, there is a second distance H2 between the backlightsource 630 and the optical fingerprint sensor 620. As the pixel area 621is a portion of the optical fingerprint sensor 620, a distance betweenthe backlight source 630 and the pixel area 621 in the verticaldirection is certainly no less than the second distance H2.

From above, due to the first distance H1 and the second distance H2, thebacklight source 630 is certainly disposed below the pixel area 621. Itcould be understood that, the backlight source 630 being disposed belowthe pixel area 621 means that the backlight source 630 is disposed lowerthan but not right under the pixel area 621. In some embodiments, thefirst distance H1 and the second distance H2 may be adjusted to make thebacklight source 630 in a suitable position, so as to improve quality ofa fingerprint image formed by the optical fingerprint module.

More detailed structures of the optical fingerprint module can be foundin the above descriptions.

Different from the embodiment shown in FIG. 7, in the embodiment asshown in FIG. 10, a light focusing lens 640 may be disposed in front ofa light emitting surface of the backlight source 630, the light focusinglens 640 may be capable of focusing light emitted from the backlightsource 630 into parallel light or near-parallel light, and the lightemitted from the backlight source 630 enters the light focusing lens 640and then enters the optical fingerprint sensor 620.

In some embodiments, the light focusing lens 640 may be a convex lens.If a distance between the backlight source 630 and the light focusinglens 640 is equal to focal length of the convex lens, the light passingthrough the light focusing lens 640 is focused to be parallel light. Insome embodiments, the focusing lens 640 may be other suitable lenses,such as a Fresnel lens.

By the above optical fingerprint module without a light guiding plate,fingerprint image recognition may be well achieved by acquiring a clearfingerprint image, a structure of the optical fingerprint module may besimplified, and cost may be reduced. Further, the light focusing lens640 which is capable of focusing the light emitted from the backlightsource 630 into parallel light or near-parallel light may be disposed infront of the light emitting surface of the backlight source 630. Thelight emitted from the backlight source 630 enters the light focusinglens 640, and then enters the optical fingerprint sensor 620. As aresult, the fingerprint image may be acquired using the parallel lightor the near-parallel light to have less distortion and higher accuracy,and thus performance of the optical fingerprint module may be furtherimproved.

In an embodiment, another optical fingerprint module is provided. FIG.11 schematically illustrates a sectional view of the optical fingerprintmodule. The optical fingerprint module includes a protective layer 710,an optical fingerprint sensor 720 and a backlight source 730.

Referring to FIG. 11, the backlight source 730 is disposed below a pixelarea 721, so that an acute angle is formed between light emitted fromthe backlight source 730 and an upper surface of the protective layer710.

The light emitted from the backlight source 730 is shown asunidirectional arrows in FIG. 11. As the backlight source 730 isdisposed below the pixel area 721, the backlight source 730 is locatedat one side of the pixel area 721 in the sectional view in FIG. 11.Still referring to FIG. 11, an area under the pixel area 721 is an areabetween the two long dotted lines, while the backlight source 730 isdisposed outside the area. Therefore, in the sectional view in FIG. 11,in a horizontal direction, there is a first distance 11 between thebacklight source 730 and the area under the pixel area 721; and in avertical direction, there is a second distance 12 between the backlightsource 730 and the optical fingerprint sensor 720. As the pixel area 721is a portion of the optical fingerprint sensor 720, a distance betweenthe backlight source 730 and the pixel area 721 in the verticaldirection is certainly no less than the second distance 12.

From above, due to the first distance 11 and the second distance 12, thebacklight source 730 is certainly disposed below the pixel area 721. Itcould be understood that, the backlight source 730 being disposed belowthe pixel area 721 means that the backlight source 730 is disposed lowerthan but not right under the pixel area 721. In some embodiments, thefirst distance 11 and the second distance 12 may be adjusted to make thebacklight source 730 in a suitable position, so as to improve quality ofa fingerprint image formed by the optical fingerprint module.

More detailed structures of the optical fingerprint module can be foundin the above descriptions.

Different from the embodiment shown in FIG. 7, in the embodiment asshown in FIG. 11, a non-opaque dielectric layer 740 may be disposedbetween the optical fingerprint sensor 720 and the backlight source 730,and the light emitted from the backlight source 730 enters thenon-opaque dielectric layer 740 and then enters the optical fingerprintsensor 720. In the embodiment, the non-opaque dielectric layer 740always has a refractive index greater than that of air, and light isenabled to enter the non-opaque dielectric layer 740 from a side surfaceof the non-opaque dielectric layer 730 which is a vertical surface or anear-vertical surface, so that the light emitted from the backlightsource 730 reaches the upper surface of the protective layer 710 with agreater incident angle (that is, the light can reach the upper surfaceof the protective layer 710 in a direction closer to be parallel to theupper surface of the protective layer 710). When the incident angle ofthe light is larger than a certain angle, total reflection occurs (i.e.,when the incident angle is greater than a critical angle, the light istotally reflected at a contact interface between the protective layer710 and air) to greatly improve quality of the image.

In some embodiments, the non-opaque dielectric layer 740 may have arefraction index above 1.2, which may further improve performance of theoptical fingerprint module.

In some embodiments, the non-opaque dielectric layer 740 may includeglass, plastic or optical adhesive.

In some embodiments, a second optical adhesive layer may be disposedbetween the optical fingerprint sensor 720 and the non-opaque dielectriclayer 740, wherein the light emitted from the backlight source 730enters the second optical adhesive layer from the non-opaque dielectriclayer 740, and then enters the optical fingerprint sensor 720 from thesecond optical adhesive layer. The second optical adhesive layer mayavoid air between the optical fingerprint sensor 720 and the non-opaquedielectric layer 740, so as to further prevent the light from beingscattered and refracted at the interface between the air and the opticalfingerprint sensor 720 or the non-opaque dielectric layer 740, which mayimprove quality of fingerprint images to be formed.

In some embodiments, a light emitting surface of the backlight source730 may be directly covered by the non-opaque dielectric layer 740, sothat the light emitted from the backlight source 730 directly enters thenon-opaque dielectric layer 740, and there is no air in the light pathfrom the backlight source 730 to the protective layer 710, which mayfurther improve quality of fingerprint images to be formed.

In an embodiment, another optical fingerprint module is provided. FIG.12 schematically illustrates a sectional view of the optical fingerprintmodule. The optical fingerprint module includes a protective layer 810,an optical fingerprint sensor 820 and a backlight source 830.

Referring to FIG. 12, the backlight source 830 is disposed below a pixelarea 821, so that an acute angle is formed between light emitted fromthe backlight source 830 and an upper surface of the protective layer810.

The light emitted from the backlight source 830 is shown asunidirectional arrows in FIG. 12. As the backlight source 830 isdisposed below the pixel area 821, the backlight source 830 is locatedat one side of the pixel area 821 in the sectional view in FIG. 12.Still referring to FIG. 12, an area under the pixel area 821 is an areabetween the two long dotted lines, while the backlight source 830 isdisposed outside the area. Therefore, in the sectional view in FIG. 12,in a horizontal direction, there is a first distance J1 between thebacklight source 830 and the area under the pixel area 821; and in avertical direction, there is a second distance J2 between the backlightsource 830 and the optical fingerprint sensor 820. As the pixel area 821is a portion of the optical fingerprint sensor 820, a distance betweenthe backlight source 830 and the pixel area 821 in the verticaldirection is certainly no less than the second distance J2.

From above, due to the first distance J1 and the second distance J2, thebacklight source 830 is certainly disposed below the pixel area 821. Itcould be understood that, the backlight source 830 being disposed belowthe pixel area 821 means that the backlight source 830 is disposed lowerthan but not right under the pixel area 821. In some embodiments, thefirst distance J1 and the second distance J2 may be adjusted to make thebacklight source 830 in a suitable position, so as to improve quality ofa fingerprint image formed by the optical fingerprint module.

Referring to FIG. 12, a non-opaque dielectric layer 840 may be disposedbetween the optical fingerprint sensor 820 and the backlight source 830,and the light emitted from the backlight source 830 enters thenon-opaque dielectric layer 840 and then enters the optical fingerprintsensor 820. In some embodiments, the non-opaque dielectric layer 840 mayhave a refraction index above 1.2, which may further improve performanceof the optical fingerprint module. In some embodiments, the non-opaquedielectric layer 840 may include glass, plastic or optical adhesive.

More detailed structures of the optical fingerprint module can be foundin the above descriptions.

Different from the embodiment shown in FIG. 11, in the embodiment asshown in FIG. 12, a side surface of the non-opaque dielectric layer 840may be a light focusing surface 841, and the light emitted from thebacklight source 830 enters the non-opaque dielectric layer 840 from thelight focusing surface 841 which focuses light emitted from thebacklight source 830 into parallel light or near-parallel light.

In the embodiment, the light focusing surface 841 of the non-opaquedielectric layer 840 is an ellipsoidal crown surface. In otherembodiments, the light focusing surface 841 of the non-opaque dielectriclayer 840 may be an oblique surface, a spherical crown surface, aconical side surface or a pyramid side surface.

In some embodiments, a lower surface of the non-opaque dielectric layermay be a light focusing surface.

By the above optical fingerprint module without a light guiding plate,fingerprint image recognition may be well achieved by acquiring a clearfingerprint image, a structure of the optical fingerprint module may besimplified, and cost may be reduced. More effect and advantages of theembodiment may be referred to the descriptions of the above embodiment.Further, the side surface of the non-opaque dielectric layer 840 servesas the light focusing surface 841 which is capable of focusing lightemitted from the backlight source 830 into parallel light ornear-parallel light. The light emitted from the backlight source 830enters the non-opaque dielectric layer 840, and then enters the opticalfingerprint sensor 820. As a result, the fingerprint image may beacquired using the parallel light or the near-parallel light to haveless distortion and higher accuracy, and thus performance of the opticalfingerprint module may be further improved.

In an embodiment, another optical fingerprint module is provided. FIG.13 schematically illustrates a sectional view of the optical fingerprintmodule. The optical fingerprint module includes a protective layer 910,an optical fingerprint sensor 920 and a backlight source 930.

Referring to FIG. 13, the backlight source 930 is disposed below a pixelarea 921, so that an acute angle is formed between light emitted fromthe backlight source 930 and an upper surface of the protective layer910.

The light emitted from the backlight source 930 is shown asunidirectional arrows in FIG. 13. As the backlight source 930 isdisposed below the pixel area 921, the backlight source 930 is locatedat one side of the pixel area 921 in the sectional view in FIG. 13.Still referring to FIG. 13, an area under the pixel area 921 is an areabetween the two long dotted lines, while the backlight source 930 isdisposed outside the area. Therefore, in the sectional view in FIG. 13,in a horizontal direction, there is a first distance K1 between thebacklight source 930 and the area under the pixel area 921; and in avertical direction, there is a second distance K2 between the backlightsource 930 and the optical fingerprint sensor 920. As the pixel area 921is a portion of the optical fingerprint sensor 920, a distance betweenthe backlight source 930 and the pixel area 921 in the verticaldirection is certainly no less than the second distance K2.

From above, due to the first distance K1 and the second distance K2, thebacklight source 930 is certainly disposed below the pixel area 921. Itcould be understood that, the backlight source 930 being disposed belowthe pixel area 921 means that the backlight source 930 is disposed lowerthan but not right under the pixel area 921. In some embodiments, thefirst distance K1 and the second distance K2 may be adjusted to make thebacklight source 930 in a suitable position, so as to improve quality ofa fingerprint image formed by the optical fingerprint module.

Referring to FIG. 13, a non-opaque dielectric layer 940 may be disposedbetween the optical fingerprint sensor 920 and the backlight source 930,and the light emitted from the backlight source 930 enters thenon-opaque dielectric layer 940 and then enters the optical fingerprintsensor 920. In some embodiments, the non-opaque dielectric layer 940 mayhave a refraction index above 1.2, which may further improve performanceof the optical fingerprint module. In some embodiments, the non-opaquedielectric layer 940 may include glass, plastic or optical adhesive. Insome embodiments, a side surface of the non-opaque dielectric layer 940may be a light focusing surface 941, and the light emitted from thebacklight source 930 enters the non-opaque dielectric layer 940 from thelight focusing surface 941 which focuses the light emitted from thebacklight source 930 into parallel light or near-parallel light.

More detailed structures of the optical fingerprint module can be foundin the above descriptions.

Different from the embodiment shown in FIG. 12, in the embodiment asshown in FIG. 13, a light anti-reflection layer 950, which is capable ofincreasing a proportion of the light emitted from the backlight source930 which enters into the non-opaque dielectric layer 940, may bedisposed on the light focusing surface 941 of the non-opaque dielectriclayer 940.

In the above optical fingerprint module without a light guiding plate,the side surface of the non-opaque dielectric layer 940 serves as thelight focusing surface 941 which is capable of focusing light emittedfrom the backlight source 930 into parallel light or near-parallellight. The light emitted from the backlight source 930 enters thenon-opaque dielectric layer 940, and then enters the optical fingerprintsensor 920. As a result, the fingerprint image may be acquired using theparallel light or the near-parallel light to have less distortion andhigher accuracy, and thus performance of the optical fingerprint modulemay be further improved.

Further, the light focusing surface 941 of the non-opaque dielectriclayer 940 may further have a light anti-reflection layer 950 formedthereon, and the light anti-reflection layer 950 is capable ofincreasing the proportion of the light emitted from the backlight source930 which enters the non-opaque dielectric layer 940. Therefore, thefingerprint image may be acquired using more light to have higherquality and accuracy, and thus performance of the optical fingerprintmodule may be further improved.

Although the present disclosure has been disclosed above with referenceto preferred embodiments thereof, it should be understood that thedisclosure is presented by way of example only, and not limitation.Those skilled in the art can modify and vary the embodiments withoutdeparting from the spirit and scope of the present disclosure.

1. An optical fingerprint module, comprising: an optical fingerprintsensor comprising a non-opaque substrate and a device layer located on asurface of the non-opaque substrate, wherein the device layer comprisesa pixel area consisting of a plurality of pixels, each of the pluralityof pixels comprises a non-opaque region and a light blocking region, thelight blocking region comprises a photosensitive element, and thenon-opaque region enables light to penetrate through the pixel area ofthe device layer; a protective layer disposed above the opticalfingerprint sensor; and a backlight source disposed below the pixelarea, wherein an acute angle is formed between light emitted from thebacklight source and an upper surface of the protective layer.
 2. Theoptical fingerprint module according to claim 1, wherein a first opticaladhesive layer is disposed between the optical fingerprint sensor andthe protective layer, wherein the light emitted from the backlightsource penetrates through the non-opaque substrate, then penetratesthrough the device layer via the non-opaque region, enters the firstoptical adhesive layer, and finally enters the protective layer from thefirst optical adhesive layer.
 3. The optical fingerprint moduleaccording to claim 1, wherein a first optical adhesive layer is disposedbetween the optical fingerprint sensor and the protective layer, whereinthe light emitted from the backlight source penetrates through thedevice layer via the non-opaque region, then penetrates through thenon-opaque substrate, enters the first optical adhesive layer, andfinally enters the protective layer from the first optical adhesivelayer.
 4. The optical fingerprint module according to claim 1, whereinthe backlight source comprises at least one Light Emitting Diode (LED),and light of the LED is at least one of near-ultraviolet light, purplelight, blue light, green light, yellow light, red light, near-infraredlight or white light.
 5. The optical fingerprint module according toclaim 1, wherein the backlight source comprises at least two LEDs whichare symmetrically arranged below the optical fingerprint sensor, andlight of the LEDs is at least one of near-ultraviolet light, purplelight, blue light, green light, yellow light, red light, near-infraredlight or white light.
 6. The optical fingerprint module according toclaim 1, wherein a light focusing lens is disposed in front of a lightemitting surface of the LED, the light focusing lens is capable offocusing light of the LED into parallel light or near-parallel light,and the light emitted from the backlight source enters the lightfocusing lens and then enters the optical fingerprint sensor.
 7. Theoptical fingerprint module according to claim 1, wherein a lightanti-reflection layer, which is capable of increasing a proportion ofthe light emitted from the backlight source which enters into theoptical fingerprint sensor, is disposed on a surface of the opticalfingerprint sensor which is close to the backlight source.
 8. Theoptical fingerprint module according to claim 1, wherein a non-opaquedielectric layer is disposed between the optical fingerprint sensor andthe backlight source, and the light emitted from the backlight sourceenters the non-opaque dielectric layer and then enters the opticalfingerprint sensor.
 9. The optical fingerprint module according to claim8, wherein a side surface or a lower surface of the non-opaquedielectric layer is a light focusing surface, and the light emitted fromthe backlight source enters the non-opaque dielectric layer from thelight focusing surface which focuses the light emitted from thebacklight source into parallel light or near-parallel light.
 10. Theoptical fingerprint module according to claim 9, wherein a secondoptical adhesive layer is disposed between the optical fingerprintsensor and the non-opaque dielectric layer, wherein the light emittedfrom the backlight source enters the second optical adhesive layer fromthe non-opaque dielectric layer, and then enters the optical fingerprintsensor from the second optical adhesive layer.
 11. The opticalfingerprint module according to claim 10, wherein a lightanti-reflection layer, which is capable of increasing a proportion ofthe light emitted from the backlight source which enters into thenon-opaque dielectric layer, is disposed on the side surface or thelower surface of the non-opaque dielectric layer.
 12. The opticalfingerprint module according to claim 9, wherein the non-opaquedielectric layer comprises at least one of glass, plastic or opticaladhesive.
 13. The optical fingerprint module according to claim 12,wherein the non-opaque dielectric layer has a refraction index above1.2.
 14. The optical fingerprint module according to claim 9, whereinthe light focusing surface of the non-opaque dielectric layer is one ofan oblique surface, a spherical crown surface, an ellipsoidal crownsurface, a conical side surface or a pyramid side surface.
 15. Theoptical fingerprint module according to claim 1, wherein the protectivelayer comprises a single layer or multiple layers, wherein a lightfiltering layer is disposed on at least one of the upper surface of theprotective layer, a lower surface of the protective layer and an uppersurface of the optical fingerprint sensor.
 16. The optical fingerprintmodule according to claim 1, wherein the device layer further comprisesa plurality of scanning lines arranged in a first axial direction and aplurality of data lines arranged in a second axial direction, whereinthe plurality of scanning lines and the plurality of data lines define aplurality of grids, and the pixels are located in the grids.
 17. Theoptical fingerprint module according to claim 2, wherein the firstoptical adhesive layer is at least one of a heat curing optical adhesivelayer, a photo curing optical adhesive layer or an optical double-sidedadhesive tape.
 18. The optical fingerprint module according to claim 10,wherein the second optical adhesive layer is at least one of a heatcuring optical adhesive layer, a photo curing optical adhesive layer oran optical double-sided adhesive tape.
 19. The optical fingerprintsensor module according to claim 5, wherein a light focusing lens isdisposed in front of a light emitting surface of the LED, the lightfocusing lens is capable of focusing light of the LED into parallellight or near-parallel light, and the light emitted from the backlightsource enters the light focusing lens and then enters the opticalfingerprint sensor.
 20. The optical fingerprint sensor module accordingto claim 3, wherein the first optical adhesive layer is at least one ofa heat curing optical adhesive layer, a photosensitive optical adhesivelayer or an optical double-sided adhesive tape.